I have an idea Tell me please how is You test server configured in Your LAN.
I bet, that:
1. Server has private IP which is NATed to public address on the router
2. Server is connected to the same router interface as rest of Your computers
3. All computers and server are in the same private address range network

I suspect, that Your test environment is as I described above, so this is the reason why <VirtualHost *:80> does not work for You.You should connect Your server to another/separate router interface then NAT will work as it should.

Yes. I will say it again, AMPPS is for local development. The way it is working now is for "local network". All the changes made in httpd-vhosts.conf are handled by AMPPS and will be rebuild by it. Configuration built by it should work in local network.

We might add an option as you have suggested.

In case this feature is not added you can create a conf file manually as you are doing now. :)